well the nos kit is just a dry kit...and there is no adjustment for fuel. You either have to run rich, or retard the timing when you are using it. This gets kind of hard on cars like ours. The best would be a wet kit. This way you dont have to do anything...the fuel is mixed in the nozzle and supplied automatically when you spray. The Zex kit is a dry kit, however they use a different method. It has a management unit that the nitrous is delivered from...all the solenoids are in that box. When the nitrous it armed....it can only be activated at WOT....it takes a voltage reading off the TPS, and will only activate past 4.2 volts.....or WOT. Other kits must use a micro switch, and you have to make brackets etc... This kit has one single wire to get that reading. Also, when the nitrous is being used...it takes a reading of bottle pressure and uses a small amount of that nitrous pressure to push harder on the fuel regulator. Under normal driving...as less vacumm is going through a motor..the higher the fuel pressure gets. Our reg. is set at 39.5psi static...at 0psi boost. At boost...1psi is about 1psi of increased fuel pressure. So at wot we have about 54psi. The zex kit will push even harder on the diaphram in the regulator making the pressure around 60psi. The increased pressure provides the added fuel for the nitrous. The kit is still a dry kit, but automatically addes more fuel for you. I had my doubts about the kit but it does indeed work. While on the dyno....when the kit was armed it read about 50psi fuel pressure. ONce the nitrous was in use the fuel pressure instantly went up to past 60psi. This proves that it works. Also...i was afraid it wasn't working so at the dyno it used the 65hp nitrous jet and the 75hp fuel jet for safety. My a/f ratio was very very rich at 9.54 : 1. I changed the jets and then it evened out to about 11.5 :1. I have a good a/f ratio...and an easy 70hp with the 65hp jets. I got mine from a local speed shop....and it was 490 brand new...next day arrival. I got a good deal, but the going rate its around 550. I also had to get a purge kit for the track which ran another 70...and also got a bottle pressure guage for more consitancy. I used the same kit # as Guss. Its for honda's or any other imports. Zex only has two kit numbers.....55-75hp for imports and 75-125 for stangs and camaros. I got the smaller kit, but the only difference is whats jets are included in the kit. SO i could jet different jets and still achieve 125hp..but thats a lot on our motors. I wouldn't go past 75hp. Any more question just ask,....i hope i answered your question.